Place Representations in the Human Visual System

对于我们的存在来说，很少有比这更基本的情况了，因为我们是会移动的生物 穿越太空。几乎所有的行为对我们的生存都是必不可少的--寻找食物，寻找配偶，以及 躲避捕食者--需要在外部世界中导航。半个世纪的研究表明 人类和动物使用世界大尺度空间结构的认知“地图”来促进这一点 才能。用于形成这些地图的大部分信息最初是从视觉获得的。但这呈现了一种 难题：我们如何转换最初从特定视图和特定视图获取的视觉空间信息 实例转换为可用于导航的环境空间的视点不变表示形式 计划？这里提出的研究将使用功能磁共振成像(FMRI)来解决 这个问题。在前人工作的基础上，我们假设人脑至少支持三个 空间表示的不同层次：(1)表示对象和表面的位置 相对于身体的各个部位，如眼睛和手(身体-空间)；(2)它代表关系 在主体的躯干和锚定在一组不可移动表面上的坐标框架之间， 定义局部场景(场景空间)；(3)表示观察者在其中的位置和方向 更大的环境，包括相对于目前“在地平线上”的位置(世界空间)。 这项研究的第一部分将研究海马区旁和海马区的场景空间表征。 脾后皮质，特别强调揭示这些 表征是从经验中学习的，并随着时间的推移而变化。第二部分建议 研究将检查神经机制涉及到代表身体空间和意志的功能 将这些机制与表示场景空间所涉及的机制区分开来。第三部分： 拟议中的研究将检查与代表世界空间有关的神经机制。虽然这件事 研究没有检查盲人的空间加工，所获得的结果将有助于我们 区分那些与视觉有着千丝万缕联系的过程和那些相对不稳定的过程。AS 这样，这些知识可能对盲人康复策略的制定至关重要。

There are few circumstances more fundamental to our existence in the fact that we are creatures that move through space. Almost all of the behaviors are essential to our survival - locating food, finding a mate, and avoiding predators - require navigation through the external world. A half-century of research suggests that humans and animals use cognitive "maps" of the large-scale spatial structure of the world to facilitate this ability. Much of the information used to form these maps is initially acquired from vision. But this presents a puzzle: how do we transform visuospatial information initially acquired from specific views and specific instances into a viewpoint-invariant representation of environmental space that can be used for navigational planning? The research proposed here will use functional magnetic resonance imaging (fMRI) to address this question. On the basis of previous work, we hypothesize that the human brain supports at least three distinct hierarchical levels of spatial representation: (1) it represents the locations of objects and surfaces relative to various body parts such as the eye and hand (body-space); (2) it represents the relationship between the trunk of the body and a coordinate frame anchored on the set of immovable surfaces that defines the local scene (scene-space); (3) it represents the the location and orientation of the observer within the larger environment, including relative to locations that are currently "over the horizon" (world-space). The first part of the proposed research will examine scene-space representations in parahippocampal and retrosplenial cortices with particular emphasis on uncovering the mechanisms by which these representations are learned from experience and change over time. The second part of the proposed research will examine the neural mechanisms involved in representing body-space and will functionally distinguish these mechanisms from those involved in representing scene-space. The third part of the proposed research will examine the neural mechanisms involved in representing world-space. Although this research does not examine spatial processing in nonsighted individuals, the results obtained will help us to distinguislvbetween processes that are inextricably tied to vision and those that are relatively amodal. As such, this knowledge could be critical for development of rehabilitation strategies in the blind.